When I learned French I used to read all the Asterix books, and then books by François Sagan who wrote pretty awful love stories - idea for me as a young teenager - I suppose the equivalent in English would be Mills and Boon stuff.
I don't mean to brag but I was sooooooooooooooo much better than my school mates and I'm sure it was from all the reading where the syntax and grammar were just being absorbed.
They used to make us read articles from Le Monde and boy were they dull and incomprehensible to boot. I don't see the point of making students slog through something dry and difficult.
Here's a post with ideas on how to improve your reading fluency